Fun today at EPFL: fast-cat robots and room mapping

LAUSANNE, SWITZERLAND – Research results in science and engineering aren’t always easy for the general public to digest, but EPFL has a bonanza this week from its various research labs, starting with a fast-cat robot that could speed up search efforts following natural disasters and accidents.

It’s all in the legs

The robot holds enormous promise, says EPFL, and it comes down to the legs: this new model meticulously reproduces the feline leg, and that’s where its strength lies.

“The ‘cheetah-cub robot’ has the same advantages as its model: it is small, light and fast. Still in its experimental stage, the robot will serve as a platform for research in locomotion and biomechanics.

“Even though it doesn’t have a head, you can still tell what kind of animal it is: the robot is definitely modeled upon a cat. Developed by EPFL’s Biorobotics Laboratory (Biorob), the “cheetah-cub robot,” a small-size quadruped prototype robot, is described in an article appearing today in the International Journal of Robotics Research. The purpose of the platform is to encourage research in biomechanics; its particularity is the design of its legs, which make it very fast and stable. Robots developed from this concept could eventually be used in search and rescue missions or for exploration.

“This robot is the fastest in its category, namely in normalized speed for small quadruped robots under 30Kg. During tests, it demonstrated its ability to run nearly seven times its body length in one second. Although not as agile as a real cat, it still has excellent auto-stabilization characteristics when running at full speed or over a course that included disturbances such as small steps. In addition, the robot is extremely light, compact, and robust and can be easily assembled from materials that are inexpensive and readily available.”

Architects and spies will love the room mapper

A second result is a new system for mapping a room that will provide the dimensions in just seconds, using four microphones that can be randomly placed.

“Blind people sometimes develop the amazing ability to perceive the contours of the room they’re in based only on auditory information. Bats and dolphins use the same echolocation technique for navigating in their environment.

“At EPFL, a team from the Audiovisual Communications Laboratory (LCAV), under the direction of Professor Martin Vetterli, has developed a computer algorithm that can accomplish this from a sound that’s picked up by four microphones. Their experiment is being published this week in the Proceedings of the National Academy of Sciences (PNAS). “Our software can build a 3D map of a simple, convex room with a precision of a few millimeters,” explains PhD student Ivan Dokmanić.”

But what’s the point? Quite a few applications are looming, including one that might interest groups like the now-famous National Security Agency in the US:

“Architects could use this to design rooms – for example concert halls or auditoriums – based upon the specific acoustics they would like to create,” says Dokmanić.

“Applications in forensic science are also on the horizon: based on several recordings of the same setup, audio waves could yield information on elements in the room that cannot be seen. In the same vein, analyzing a telephone call from a person who is moving around a room could allow investigators to identify where the person is calling from.

“Finally, it might be possible to implement this algorithm in mobile devices and use them to deduce location information inside buildings – a place where GPS signals do not penetrate well. “There are already many applications, and we foresee many more. This is only the beginning!” concludes Dokmanić.

Leprosy findings show genetic shift

And a third is confirmation of suspicions that a sudden drop in the number of leprosy cases in medieval times was due to a genetic shift, not a change in the pathogen.

“At the turn of the 16th century, the disease abruptly receded over most of the continent. The event was both sudden and inexplicable. Perhaps the pathogen that causes leprosy had evolved into a less harmful form? To find out, an international team of biologists and archaeologists joined forces. They decoded the nearly complete genome from five strains of Mycobacterium leprae, the bacterium responsible for leprosy, which they collected and reproduced by digging up the remains of humans buried in medieval graves. Reconstructing the bacterial genomes was no easy task, as the material available—from the human remains—contained less than 0.1% of bacterial DNA. The researchers developed an extremely sensitive method for separating the two kinds of DNA and for reconstituting the target genome with an unprecedented level of precision. “We were able to reconstruct the genome without using any contemporary strains as a basis,” explains study co-author and EPFL scientist Pushpendra Singh, who worked closely with Johannes Kraus and team from Tubingen University in Germany.

“The results are indisputable: the genome of the medieval strains is almost exactly the same as that of contemporary strains, and its mode of action has not changed. “If the explanation of the drop in leprosy cases isn’t in the pathogen, then it must be in the host, that is, in us; so that’s where we need to look,” explains Stewart Cole, co-director of the study and the head of EFFL’s Global Health Institute.”